PRN     Azimuth(d)     Elevation(d)   Vertical-TEC(tecu)    Slant-TEC(tecu)       S4(L1/L2)    2017/12/20-16:27:50
G10     294.7          50.5                6.1 +/-    2.58       7.7 +/-    2.58  0.070 / 0.070
G15     46.1           28.0                4.8 +/-    1.18       8.8 +/-    1.18  0.050 / 0.100
G18     0.2            66.0                6.1 +/-    0.35       6.6 +/-    0.35  0.080 / 0.180
G20     69.4           21.4                5.0 +/-    0.75      10.7 +/-    0.75  0.080 / 0.210
G21     101.4          70.1                8.0 +/-    0.91       8.4 +/-    0.91  0.080 / 0.100
G24     100.3          26.0                7.1 +/-    1.23      13.5 +/-    1.23  0.070 / 0.120
G27     300.6          34.4                5.7 +/-    1.79       9.2 +/-    1.79  0.090 / 0.110
G32     210.4          30.0                8.6 +/-    1.13      15.1 +/-    1.13  0.080 / 0.150